This invention relates to a packaging method of circuit elements for an electronic watch such as an IC chip or an oscillator etc. which are fixed on a base plate.
In a conventional electronic watch, after a packaged IC chip and other circuit elements are fixed on a printed circuit board, the assembled board is incorporated in a watch. Such a construction is disadvantageous because a large space is required for housing the electronic circuit, a complicated assembling process is needed to assemble the watch, thereby making it difficult to lower the manufacturing cost, and such watches were lacking in reliability.
For overcoming the above defects, it has been proposed to fix a base IC chip directly to a printed circuit board together with other circuit elements. However, according to this method, it is not possible to us an automatic bonding machine of the heat-pressing type using gold wire for wire bonding between the IC chip and the printed conductors, and therefore the bonding process can not be carried out efficiently. Moreover, to make matters worse, the shape of the printed circuit board can not be choose freely to fit the other watch parts.